US Patent Publication 2003/0127440 discloses a pallet changer associated with a processing machine, such as a laser-cutting machine. This pallet changer includes an upper and lower pallet, which are driven in alternation into the laser-cutting machine to process the sheet-like material resting on a support surface of the pallet. After the processing of the sheet-like material, the pallet is removed from the processing machine and is returned to the pallet changer, wherein the second pallet in the meantime has been loaded with a further sheet-like material and driven into the processing machine. By means of a pallet changer of this type, while the sheet-like material on a loaded pallet driven into the processing machine is being processed, the pallet located in the pallet changer is loaded with a sheet-like material for the subsequent processing operation. The sheet-like material already processed is driven out from the processing machine, and the pallet with the processed sheet-like material is unloaded and then loaded with a further sheet-like material to be processed.
The processing period of the sheet-like material in the processing machine, which is also referred to as the “primary processing time,” takes more time than the unloading of the processed sheet-like material and the loading of a sheet-like material to be processed, which is also referred to as the “secondary working time.” Due to the shorter secondary working time of the pallet changer compared to the primary processing time of the processing machine, there are many downtime periods at the pallet changer.
Additional processing steps are performed outside the pallet changer in separate process steps, such as the labelling or marking of the sheet-like material, the forming of holes, deburring, thread tapping, or the like. This requires space. If these additional processing operations are not performed in separate processing stations, but instead by the processing machine, the primary processing time is extended by these additional processing operations.